. and a conservative america. there is the united states of america. >> obama gave the speech, the keynote, 2004, four years later, he's president. does this lie ahead for julian castro? >> he lived in illinois. i live in texas. it's one of the reddest states in the whole nation. >> reporter: there are ghosts in this convention center for anyone delivering the keynote. ghosts of surgery,ful and unsuccessful keynotes gone by. >> my fellows. >> reporter: in 1988, the keynote by bill clinton at the dnc was widely jeered and almost derailed his career. and yet, four years later, clinton was elected president. but there are plenty of speakers no one remembers. julian castro feels the pressure. why did obama pick you? >> i think that he and i see eye to eye on a lot of issues. i also think it's another signifier of the significance of h himself pan hispanics. >> reporter: his mother immigrated to the country, his brother joaquin is now running for congress. he's expected to win. tonight, he introduced julian. >> ours is a nation like no other. a place where great journeys can be made in a single generation.